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Abstract:

An engine cover and method of making the same with a textured surface
with an in-mold coating. A noise abatement cover for top of an engine has
a textured, in-mold coated, high quality outer appearance with a core of
medium density polyurethane. The method of making the cover includes
applying a mold release to grained aluminum tool and applying coating to
at least one side of the grained aluminum tool to form an in-mold coating
on the resulting engine cover, which is preferably a single piece.

Claims:

1. An engine cover adapted to be used on top of an engine comprising: a
core of medium density polyurethane; and an aesthetically textured outer
surface with an embedded coating wherein the outer surface has a
show-quality outer surface appearance.

2. The engine cover of claim 1 wherein the engine cover is a single
piece.

3. The engine cover of claim 1 wherein the coating is in-molded
urethane-based paint that provides consistent color, gloss and UV
protection on the outer surface.

4. The engine cover of claim 1 wherein the core is high temperature
polyurethane with a density of 5-13 PCF and provides a high level of
sound absorption in close association with the engine.

5. The engine cover of claim 1 wherein an inner surface of the engine
cover does not have a coating, wherein the inner surface faces the
engine.

7. The engine cover of claim 5 having protrusions extending from the
inner surface adapted to engage the engine so the outer surface does not
sag when installed on the engine.

8. A noise abatement engine cover for an engine comprising: a core of
medium density foam with a density of 5-13 PCF that provides a high level
of sound absorption in close association with the engine; and a textured
outer surface with an embedded coating that provides color and UV
protection; wherein the engine cover is an integral piece.

9. The noise abatement engine cover of claim 8 wherein an inner surface
of the engine cover that is adjacent to the engine does not have a
coating and is raw polyurethane foam.

10. A method of making an engine cover with a textured surface including
steps of: applying mold release to an aluminum tool having a grained
side, applying coating to the grained side of the aluminum tool that is
applied with mold release, dispensing foam into a cavity of the aluminum
tool, allowing foam to expand in the cavity and cure, and extracting from
the tool the engine cover having the textured surface with the coating.

11. The method of claim 10 wherein the coating is urethane-based paint.

12. The method of claim 10 wherein the coating is 0.0008 to 0.0025 inch
thick.

13. The method of claim 10 including the additional step of controlling
temperature of the aluminum tool during expanding and curing of the foam.

14. The method of claim 10 wherein the engine cover is a single piece.

15. The method of claim 10 wherein the foam is high temperature
polyurethane with a density of 5-13 PCF.

16. The method of claim 10 where a second side of the aluminum tool is
not coated with a coating.

17. The method of claim 10 wherein the cavity forms the shape of the
engine cover and the grained side of the aluminum tool forms the textured
surface on the engine cover.

Description:

FIELD OF THE DISCLOSURE

[0001] This disclosure relates to a noise abatement cover used on top of
an engine and method of making the same. More specifically, the noise
abatement engine cover includes molded foam with a high quality outer
surface appearance.

BACKGROUND

[0002] A variety of devices, using various materials and processes,
provide noise abatement performance for automobiles: (1) plastic
injection molded covers and those with added sound absorbers (2)
fiberglass, (3) die-cut or molded (cast) foam and (4) high density foam.

[0005] Die-cut or molded (cast) foam provides a level of sound absorption,
but not quality surface appearance. As noted, this can be used alone, but
also in combination with other components.

[0006] The automotive industry uses foam material for noise abatement.
Polyurethane foam is known for acoustical panels for sound barrier
dampening and sound absorbsion. It reduces passenger compartment noise
including in the engine compartment with polyurethane foam technology,
including a sound absorption panel as a shaped component adapted to an
engine compartment. Published Patent Application 2007/0287001 discloses a
sound-absorbing compartment lining having a foam material layer and fiber
layer made from mineral fibers. Another example for an automotive engine
hood is as shown in U.S. Pat. No. 4,584,232. It discloses a sound
absorbing member including a fiber grid insert disposed between and
bonded to two open cell foam panels. Similarly, U.S. Pat. No. 4,288,490
discloses an engine hood lining for automotive vehicles having a
continuous sheet-like body that is formed of a closed-cell polyethylene
foam material and is shaped to fit the inside contour of a hood of the
vehicle.

[0007] High density (i.e. 19 PCF) micro-cellular foam provides
barrier/damper performance and good appearance, but not a high level of
sound absorption performance.

[0008] Such a cover for the top of an engine is produced in Germany for
the Mini Cooper, using high density, micro-cellular foam at approximately
15-19 PCF (240-300 kg/m3), Carcoustics (of Germany) is a Tier-2
supplier of engine cover for the Mini Cooper. Baur Formschaumtechnik (of
Mindelheim Germany) is the Tier-3 molder of part. High density foam does
not provide a high level of sound absorption performance. As such,
certain foam products are used in close association with the engine.

[0009] U.S. Pat. No. 4,863,791 discloses sound absorption in foam core
panels including a method of manufacture of a foam core and vehicle trim
panels made from such board. A foam board having a cell structure
including a structure with large cells in a center portion is initially
formed. This board is skived into two separate panels, each having one
surface with relatively large cell structure and wherein said cells have
been opened by the skiving process. This surface acts to promote enhanced
sound absorption from the foam core board. This board may be laminated
with appropriate decorative material and molded to make contoured
resilient vehicle trim panels.

[0011] The present disclosure provides a molded foam part that provides
improved appearance (beauty) and noise abatement. The engine cover
provides both high quality sound absorption performance and high quality
1st surface appearance. The preferred single piece construction
provides a first surface quality appearance, in-mold painted, textured,
noise abatement cover used for the top of engine. The construction of the
engine cover is different from the prior art in being an integral part
with a unique combination of materials made by a certain process to
obtain both quality appearance and noise abatement properties.

[0012] The type of materials used to obtain appearance and sound
absorption characteristics are important. The preferred molded engine
cover includes an in-mold paint coating with medium density polyurethane
foam (i.e. 5-13 PCF density) to provide a show-quality surface appearance
part with noise abatement properties. The engine cover has NVH (Noise,
Vibration and Harshness) performance enhancements over existing engine
covers. The construction, process, and materials all enhance NVH
characteristics.

[0013] The process used to obtain appearance and sound absorption
characteristics is important. The preferred method of making an engine
cover includes: [0014] applying, such as spraying, wax-based mold
release to a grained aluminum tool, which is preferably temperature
controlled; [0015] applying coating, such as urethane-based paint,
0.0008-0.100'' thick, to the grained aluminum tool, coated with mold
release; [0016] dispensing polyurethane foam into the grained aluminum
tool; [0017] allowing foam to expand in a tool cavity and cure; and
[0018] extracting a part from the grained aluminum tool to function as an
engine cover.

[0019] From the preferred process results a noise abatement cover used for
top of an engine with a textured, in-mold coated, high quality outer
appearance.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above-mentioned and other features of this disclosure and the
manner of obtaining them will become more apparent, and the disclosure
itself will be best understood by reference to the following descriptions
of engine covers and methods taken in conjunction with the accompanying
figures, which are given as non-limiting examples only, in which

[0022]FIG. 2 shows a bottom view of an inner surface of the noise
abatement engine cover.

[0023] The exemplifications set out herein illustrate embodiments of the
disclosure that are not to be construed as limiting the scope of the
disclosure in any manner. Additional features of the present disclosure
will become apparent to those skilled in the art upon consideration of
the following detailed description of illustrative embodiments
exemplifying the best mode of carrying out the disclosure as presently
perceived.

DETAILED DESCRIPTION

[0024] While the present disclosure may be susceptible to embodiments in
different forms, the figures show, and herein described in detail,
embodiments with the understanding that the present descriptions are to
be considered exemplifications of the principles of the disclosure and
are not intended to be exhaustive or to limit the disclosure to the
details of construction and the arrangements of components set forth in
the following description or illustrated in the figures.

[0025] As shown in FIG. 1, an engine cover 10 includes a textured outer
surface 12 with an embedded coating 14 and an inner surface 16 that faces
the engine. The engine cover 10 is preferably a single piece.

[0026] The outer surface 12 can receive its texture from grained aluminum
tool that forms part of the cavity during the molding process. The
coating 14 can be an in-mold coating, such as urethane-based paint that
provides consistent color, gloss and UV protection.

[0027] The inner surface 16 may or may not have a coating. But preferably
the inner surface 16 of the engine cover 10 does not have a coating. The
inner surface 16 may be raw polyurethane.

[0028] The core of the engine cover 10 is medium density foam, such as
polyurethane with a density of 5-13 PCF (80-208 kg/m3). Due to
engine heat, the preferred polyurethane core is high temperature
polyurethane.

[0029] The engine cover 10 may have a series of apertures 18, 20 and 22 as
clearance holes or potentially to help secure the engine cover 10 to an
engine. Attachment element 36 can be used as an attachment feature to
secure the engine cover 10 to an engine. The engine cover 10 may have a
depression 24 on a portion of the top outer surface 12 that is a pocket
or recess for a name plate, label, logo or badge.

[0030] The inner surface 16 may protrusions 26, 28, 30, 32 and 34 on the
bottom of the engine cover 10 to support the foam, so the outer surface
12 does not sag or warp. The protrusions 26, 28, 30, 32 and 34 extend
from the inner surface 16 and are adapted to engage an engine upon with
the engine cover 10 is attached.

[0031] The method of making the engine cover 10 with an appealing outer
surface includes several steps. Preferably, the cavity within which the
molded cover is formed is preferably a grained aluminum tool with a least
one grained side to produce a textured surface of the engine cover 10. A
mold release, such as a spray, wax-based compound, can initially be
applied to the grained aluminum tool, on both the preferred grained side
and a second side. After the grained aluminum tool is coated with mold
release, a coating is applied, such as by spraying, to at least one side
of the grained aluminum tool, primarily the grained side. The coating can
be a urethane-based paint that can be applied 0.0008-0.100'', with
0.001-0.0025'' as a preferred thickness. Paint can form an in-mold,
embedded coating 14 on the resulting engine cover 10 providing consistent
color, gloss and UV protection. Another option for top coating is a
urethane spray skin (0.7 mm to 7.5 mm). If no in-mold coating is applied
on a second side of an aluminum tool that shapes the inner surface of the
engine cover 10, that inner surface 16 of the resulting engine cover 10
will be uncoated raw foam.

[0032] Foam can be dispensed into a cavity of the grained aluminum tool to
fill the cavity in the shape of the engine cover 10. The foam is allowed
to expand in tool cavity and cure. The foam is preferably medium density
polyurethane, such as high temperature polyurethane with a density of
5-13 PCF (80-208 kg/m3)

[0033] The tool is opened and an engine cover 10 can be extracted having a
textured outer surface 12 with an in-mold applied coating 14. A noise
abatement engine cover 10 with a textured, in-mold coated, high quality
outer appearance can result. The resulting engine cover 10 is preferably
a single piece.

[0034] Emblems or labels can be attached to the engine cover 10, such as
in depression 24, on a portion of the top outer surface 12.

[0035] Controlling temperature is desired for the grained aluminum tool
before initially applying mold and during the expanding and curing of the
foam.

[0036] This disclosure has been described as having exemplary embodiments
and is intended to cover any variations, uses, or adaptations using its
general principles. It is envisioned that those skilled in the art may
devise various modifications and equivalents without departing from the
spirit and scope of the disclosure as recited in the following claims.
Further, this disclosure is intended to cover such variations from the
present disclosure as come within the known or customary practice within
the art to which it pertains.